Private messages
One-to-one conversations are end-to-end encrypted on your device, with cryptography resistant to quantum computers — the server carries them, it does not read them.
What "end-to-end" means here
Encryption and decryption happen in your browser. The secret keys never leave the device, and what travels over the network is the already-encrypted text.
This holds for the voice rooms and for the ephemeral rooms too, with the same techniques.
Resistant to quantum computers
The key exchange uses ML-KEM and the sender's signature uses ML-DSA — algorithms chosen because they resist quantum computing attacks, and not only today's attacks. It is a decision about the future of conversations that stay stored.
Automatic translation is the exception, and it warns you
Translating a message automatically means sending its text to a translation service — that is, outside the end-to-end envelope.
That is why translation ships turned off, and the trade-off is explained at the moment you decide to turn it on. It is not fine print: it is the choice presented where it happens.
If messages show up as unavailable
When the message transport is not configured in the environment, the screen says it is unavailable instead of simulating a conversation. A fake transport in an end-to-end feature would be a security lie, and the product prefers to admit the failure.